Buffering device for chair

ABSTRACT

A buffering device for chair is disposed between a first part of a chair and a second part which is capable of pivoting with respect to the first part and between a first position and a second position. The buffering device is capable of keeping driving the second part to swivel back to the first position, and when the second part is located at the second position, the amount of deformation of an elastic member of the elastic member increases.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a buffering device, and more particularly to a buffering device for chair.

2. Description of the Prior Art

Among the conventional chairs, there is a type of chair whose back is 360 degree rotatable. However, the disadvantages of this rotatable back are that: when the length of the chair back extends to the user s shoulder or even to the head, the position of the center of gravity of the chair back is different from the location where the chair back is pivotally connected, the chair back will be tilted automatically because of its gravity to an improper angle at which the user will feel uncomfortable. Further, the supporting force to the user given by the frame of the chair back also seems to be weak. Hence, it is necessary to arrange a buffering device between the back and the seat of the chair.

The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.

SUMMARY OF THE INVENTION

The primary object of the present invention is to provide a buffering device for a chair, which enables the chair to provide a better supporting effect.

To obtain the above object, a buffering device for chair, is disposed between a first part of a chair and a second part which is capable of pivoting with respect to the first part and between a first position and a second position, and comprises:

an extending portion extending from an appropriate portion of the second part, and on the extending portion being defined a restriction slot;

a fixing rod located corresponding to the extending portion and including a first end to be inserted in a mounting portion fixed to the first part, a second end, and a radially extended flange between the first and second ends;

a bolt is inserted in the second end of the fixing rod and the restriction slot of the extending portion such that a travel of the second end of the fixing rod is restricted within the restriction slot, and

an elastic member biased between the first end of the fixing rod and the flange, in such a manner that the elastic member has one end abutted against the flange and the other end abutted against the mounting portion;

wherein the elastic member keeps abutting against the mounting portion and the flange of the fixing rod all the time, the fixing rod can support the extending portion, and the second part will be pushed back to the first position when it is not subjected to any external force, when the second part is subjected to an external force and pivots towards the second position, an amount of deformation of the elastic member is increased.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded view of a buffering device for chair in accordance with a first embodiment of the present invention;

FIG. 2 is an assembly view of the buffering device for chair in accordance with the first embodiment of the present invention;

FIG. 3 shows a first position of the buffering device for chair in accordance with the first embodiment of the present invention;

FIG. 4 shows a second position of the buffering device for chair in accordance with the first embodiment of the present invention;

FIG. 5 is a side view of a buffering device for chair in accordance with a second embodiment of the present invention;

FIG. 5A is a part of FIG. 5;

FIG. 6 is a side view of a buffering device for chair in accordance with a third embodiment of the present invention;

FIG. 6A is another side view of the buffering device for chair in accordance with the third embodiment of the present invention;

FIG. 7 is an exploded view of a buffering device for chair in accordance with a fourth embodiment of the present invention;

FIG. 7A is a side view of a part of the buffering device for chair in accordance with the fourth embodiment of the present invention;

FIG. 7B is another side view of the part of the buffering device for chair in accordance with the fourth embodiment of the present invention;

FIG. 8 is a side view of a buffering device for chair in accordance with the fifth embodiment of the present invention; and

FIG. 8A is another side view of the buffering device for chair in accordance with the fifth embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be clearer from the following description when viewed together with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiment in accordance with the present invention.

Referring to FIGS. 1-3, a first embodiment of the present invention is shown, wherein the chair comprises: a body 10, a back 20 and two buffering devices 30.

The body 10 includes a seat 11 and a supporting portion 13. The seat 11 extends upward to form a pair of connecting portions 111. The supporting portion 13 is disposed at the bottom of the seat 11 to support the body 10. In addition, it can be provided with a pair of armrests according to user s requirement, for example, the armrests can be mounted on the top of both sides of the seat 11. At this embodiment, the connecting portions 111 can also be used as armrests.

The back 20 includes a pair of pivots 21 which are to be pivotally jointed to the free ends of the connecting portions 111 for allowing the back 20 to be pivotable between a first position and a second position. In this embodiment, the back 20 includes two rods 22 and a plurality of transverse shafts (not shown) inserted between the two rods 22. On each of the transverse shafts are rotatably inserted two sleeves 24 whose surface is formed with protrusions, and the pivots 21 are disposed in the rods 22.

In this embodiment, the buffering devices 30 are disposed between the body 10 and the back 20 of the chair. At this moment, the seat 11 of the seat 10 is the first part and the back 20 is the second part. More specifically, the two buffering devices 30 are disposed between the rods 22 of the back 20 and between both sides of the seat 11. Each of the buffering devices 30 includes an extending portion 31, a fixing rod 32, a mounting portion 33, a bolt 34 and an elastic member 35.

Since the two buffering devices 30 are exactly the same, and for easy explanation, the following description is based on one buffering device 30 only. The extending portion 31 extends backwards from an appropriate portion of the corresponding rod 22 of the back 20, such as, from a portion of the rod 22 close to the corresponding pivot 21. In the extending portion 31 is defined a restriction slot 311. The fixing rod 32 is located corresponding to the extending portion 31 and includes a first end 321 to be inserted in the mounting portion 33, a second end 322 with a through hole (not shown), and a radially extended flange 324 between the first and second ends 321, 322.

The mounting portion 33 is fixed to the body 10. In this embodiment, the mounting portion 33 is fixed to the seat 11 and includes a compensating member 331 and two mounting pieces 332 with two holes (not shown). A part of the compensating member 331 is fixed to the seat 11, and the mounting pieces 332 are disposed at appropriate portions of the compensating member 331. The holes of the mounting pieces 332 are provided for insertion of the first end 321 of the fixing rod 32.

The bolt 34 is inserted in the hole of the fixing rod 32 and the restriction slot 311 of the extending portion 31 in such a manner that the travel of the second end 322 of the fixing rod 32 is restricted within the restriction slot 311. The elastic member 35 is inserted on the fixing rod 32 and biased between the first end 321 and the flange 324, and more specifically, the elastic member 35 has one end abutted against the flange 324 and the other end abutted against one of the mounting pieces 332 of the mounting portion 33 close to the flange 324.

As shown in FIG. 3, the elastic member 35 keeps abutting against the mounting portion 33 and the flange 324 of the fixing rod 32 all the time, since the mounting portion 33 is fixed to the body 10, the fixing rod 32 can support the extending portion 31, and the back 20 will be pushed back to its first position when it is not subjected to any external force. Referring then to FIG. 4, when it is subjected to an external force, for example, the user s back rests against the back 20, the back 20 will pivot towards the second position, at this moment, the amount of deformation of the elastic member 35 is increased, and the bolt 34 slides within the restriction slot 311 of the extending portion 31.

Referring to FIG. 5, a second embodiment of the present invention is shown, wherein the chair further comprises a headrest 40 which also has two shafts 41 connected to the back 20. Between the headrest 40 and the back 20 are disposed a left device and a right buffering device. At this moment, the back 20 is the first part, and the headrest 40 is the second part. The buffering devices 50 between the headrest 40 and the back 20 are the same as the buffering devices 30, so no further explanation is necessary. As shown in FIG. 5A, when the headrest 40 is subjected to an external force, it can also pivot about the shaft 41, and when it is not subjected to an external force, the headrest 40 can be driven back to its original position by the buffering devices 50.

Referring to FIG. 6, a third embodiment of the present invention is shown, wherein the chair further comprises a plurality of knuckles 60 which are pivotally connected to one another. Between every two neighboring knuckles 60 are disposed a left and a right buffering devices 50. And in every two neighboring knuckles 60, the top knuckle 60 is always pivotable with respect to the lower knuckle 60, at this moment, the lower knuckle 60 is the first part and the top knuckle 60 is the second part. In addition, the lowest two of the whole knuckles 60 are connected to the connecting portions 111 of the seat 11, and between these two lowest knuckles 60 and the seat 11 are also disposed a left and a right buffering devices 50, here, the seat 11 is defined as the first part and the two lowest knuckles 60 as a whole are defined as the second part. As shown in FIG. 6A, these knuckles 60 will swivel backward when they are subjected to an external force, and when they are not subjected to any external force, these knuckles 60 will be driven back to their original positions by the buffering devices 50.

Referring then to FIG. 7, a fourth embodiment of the present invention is shown, wherein the body 10 of the chair only comprises a seat 11. A connecting portion 111 extends from the rear portion of the seat 11 upward, and the pivot 21 of the back 20 is pivotally connected to the free end of the connecting portion 111. At this moment, the seat 11 is the first part, and the back 20 is the second part. In this embodiment, the connecting portion 111 is also used as a compensating member, namely, at appropriate portions of the connecting portion 111 are disposed mounting pieces 332. One end of the extending portion 31 of the buffering device 30 is fixed to an appropriate portion of the back 20. By such arrangements, the back 20 is in its original position before it is subjected to an external force, and when an external force is applied to the back 20, the back 20 will compress the elastic member 35 to change its angle with respect to the seat 11 to better support the user s back. In this embodiment, the chair further comprises a headrest 40, and between the headrest 40 and the back 20 is also arranged a buffering device 50 which is similar to the buffering device 30 and used to adjust the angle between the headrest 40 and the back 20.

Referring then to FIGS. 7A and 7B, the buffering device 30 further comprises two fixing nuts 36, and the fixing rod 32 is partially formed with a threaded section 37 on which the two fixing nuts 36 are engaged, so as to allow the user to selectively adjust the height of the fixing nuts 36. The radial length of the fixing nuts 36 is larger than the diameter of the through hole (not shown) of the mounting piece 332, one of the fixing nuts 36 is located between the two mounting pieces 332, which limits the travel of the fixing nut 36 and also restricts the pivotable angle of the back 20 with respect to the seat 11. Further, another fixing nut 36 is located close to the first end 321 of the fixing rod 32 to restrict the return angle of the back 20.

FIGS. 8 and 8A, a fifth embodiment of the present invention is shown, wherein the headrest 40 comprises a pivot 41 which is pivotally connected to a connecting portion 25 extending from the top of the back 20, hence, the back 20 is the first part, and the headrest 40 is the second part. Between the headrest 40 and the back 20 is also arranged a buffering device 50 to drive the headrest 40 back to its original position when the headrest 40 is subject to no external force, as shown in FIG. 8.

In the present invention, the mounting portions can also be fixed to other portions of the body of the chair, such as to the armrests which are fixed to the seat or to the supporting portion (if the chair has such a supporting portion). On top of that, a restriction slot which is provided for insertion of a bolt can also be directly defined in the back of the chair in stead of arranging an extending rod on the back which is used as a second part. At the first end of the fixing rod can also be disposed an anti-disengagement bolt whose length is larger than the radial length of the through holes of the mounting pieces, so as to prevent the fixing rod from disengaging from of the through holes of the mounting pieces under the effect of the elastic member.

While we have shown and described various embodiments in accordance with the present invention, it is clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention. 

1. A buffering device for chair, disposed between a first part of a chair and a second part which is capable of pivoting with respect to the first part and between a first position and a second position, and comprising: an extending portion extending from an appropriate portion of the second part, and on the extending portion being defined a restriction slot; a fixing rod located corresponding to the extending portion and including a first end to be inserted in a mounting portion fixed to the first part, a second end, and a radially extended flange between the first and second ends; a bolt being inserted in the second end of the fixing rod and the restriction slot of the extending portion such that a travel of the second end of the fixing rod is restricted within the restriction slot, and an elastic member biased between the first end of the fixing rod and the flange, in such a manner that the elastic member has one end abutted against the flange and the other end abutted against the mounting portion; wherein the elastic member keeps abutting against the mounting portion and the flange of the fixing rod, the fixing rod can support the extending portion, and the second part will be pushed back to the first position when it is not subjected to any external force, when the second part is subjected to an external force and pivots towards the second position, an amount of deformation of the elastic member is increased.
 2. The buffering device for chair as claimed in claim 1, wherein the mounting portion includes a compensating member and a mounting piece with a hole, a part of the compensating member is fixed to the first part, and the mounting piece is disposed at an appropriate portion of the compensating member, the hole of the mounting piece is provided for insertion of the first end of the fixing rod, and one end of the elastic member which is away from the flange is abutted against the mounting piece.
 3. The buffering device for chair as claimed in claim 2, wherein an anti-disengagement bolt is disposed at the first end of the fixing rod.
 4. The buffering device for chair as claimed in claim 1 further comprising a fixing nut, the mounting portion including a compensating member and two mounting pieces which are arranged at different heights, and each mounting piece having a hole, wherein a part of the compensating member is fixed to the first part, and the mounting pieces are disposed at appropriate portions of the compensating member, one end of the elastic member which is away from the flange is abutted against one of the mounting pieces which is close to the flange, the fixing rod is partially formed with a threaded section on which the fixing nut is engaged, a radial length of the respective fixing nuts is larger than a diameter of the hole of each of the mounting pieces, and the fixing nut is located between the two mounting pieces.
 5. A buffering device for chair, disposed between a first part of a chair and a second part which is capable of pivoting with respect to the first part and between a first position and a second position, and comprising: a fixing rod located corresponding to a restriction slot of the second part and including a first end to be inserted in a mounting portion fixed to the first part, a second end, and a radially extended flange between the first and second ends; a bolt being inserted in the second end of the fixing rod and the restriction slot of the second part such that a travel of the second end of the fixing rod is restricted within the restriction slot, and an elastic member biased between the first end of the fixing rod and the flange, in such a manner that the elastic member has one end abutted against the flange and the other end abutted against the mounting portion; wherein the elastic member keeps abutting against the mounting portion and the flange of the fixing rod all the time, the fixing rod can support the second part, and the second part will be pushed back to the first position when it is not subjected to any external force, when the second part is subjected to an external force and pivots towards the second position, an amount of deformation of the elastic member is increased.
 6. The buffering device for chair as claimed in claim 5, wherein the mounting portion includes a compensating member and a mounting piece with a hole, a part of the compensating member is fixed to the first part, and the mounting piece is disposed at an appropriate portion of the compensating member, the hole of the mounting piece is provided for insertion of the first end of the fixing rod, and one end of the elastic member which is away from the flange is abutted against the mounting piece.
 7. The buffering device for chair as claimed in claim 6, wherein an anti-disengagement bolt is disposed at the first end of the fixing rod.
 8. The buffering device for chair as claimed in claim 5 further comprising a fixing nut, the mounting portion including a compensating member and two mounting pieces which are arranged at different heights, and each mounting piece having a hole, wherein a part of the compensating member is fixed to the first part, and the mounting pieces are disposed at appropriate portions of the compensating member, one end of the elastic member which is away from the flange is abutted against one of the mounting pieces which is close to the flange, the fixing rod is partially formed with a threaded section on which the fixing nut is engaged, a radial length of the respective fixing nuts is larger than a diameter of the hole of each of the mounting pieces, and the fixing nut is located between the two mounting pieces. 